1. Field of the Invention
This invention generally relates to a bicycle force sensing assembly. More specifically, the present invention relates to a bicycle force sensing assembly for sensing a pedaling force being applied to a crank axle.
2. Background Information
Bicycles are sometimes equipped with a force sensor for detecting a force acting on the bicycle crank axle. For example, in U.S. Pat. No. 7,516,677 (assigned to Shimano Inc.), a cylindrical torsion-detecting sleeve member (force sensor unit) is provided on a crank axle for detecting a torque applied to the crank axle. Another example of a force sensor for detecting force acting on the bicycle crank axle is disclosed in EP Patent Publication No. 1,361,822. In this patent publication, sensors are positioned between a radial inner surface of the bottom bracket tube and a radially extending outer surface of an annular member that surrounds one of the crank axle bearings. With these arrangements, the strain sensors only detect the pedaling force acting on the bicycle crank axle from one leg. Thus, with these arrangements, the calculated pedaling force can sometimes be inaccurate.